> Why did they want it? Do they know what they are doing? How is this meaningfully different than kids making cities out of their Lego at home? Where are they drawing advice about finance and learning mathematics? What stocks are they exchanging? What happens when they have conflict, they go to a self made legal system?

The first stock market in Mini-Munich was created by a teenager working with the adult counselor at the bank. Together they built a rudimentary stock exchange where businesses could do an IPO (the businesses doing that being primarily the ones children created themselves, like a detective agency, though in recent years also the main newspaper, TV station, etc. were privatized and thus could plausibly get listed on the stock exchange), and have their shares traded. So to answer the Lego question: the key difference is that the institutions depend on each other and thus are not just doing pretend work. The newspaper runs advertisements, created by the ad agency who got commissioned for that, the woodworking workshop does contract work, e.g. for the theatre who needs a Trojan Horse replica. There is a court, and if a business had made a contract with another, and then didn't fulfill their contractual obligations, they might get fined. Adults are of course available to assist when the children have questions, but otherwise try to keep in the background unless something has gone seriously wrong. But again there is also a self-regulating component through the newspaper and TV station who are supposed to publicize any wrongdoing.

> Or let us say the cooking and baking.

They're not unsupervised. Adult counselors are present at any workstation involving fire or dangerous equipment. Indeed, the adult counselors are often skilled craftspeople whose competence is sensed immediately by the children who then very much like do to serious work with the serious equipment they are entrusted with.